Experiment: Growing germs, Part 2: See if some germs grew.

Objective
Have students see the reality of germs and the value of soap.

Time
10 minutes

What You Need
Germ growing kits from Growing Germs: Part 1.

Activity
Examine each cup from Growing Germs: Part 1 every day or 2. In a few days, you should see murkiness in some of the cups. With luck, there are

Note: Do not wait too long, as all the cups will probably grow murky because the procedures were not sterile.
 * Very few germs in Cup A the control where you did nothing and the soup was (fairly) sterilize.
 * Lots of germs in Cup B, where a child dipped one unwashed hand into Mug B.
 * Few germs in Cup C, where the child washed hands carefully and dipped the other hand.
 * Lots of germs in Cup D, where you dipped something really yucky.

 If Cups A to D are not clear, pour them in order into 4 clear glasses.

Explain that although germs are incredibly tiny, so many millions of them grew that the glass became visibly murky.

Note: Clean your hands very well. Wash all cups and glasses very thoroughly. Then put all cups and glasses in boiling water for 3 minutes (if it won’t harm the glasses).

Alternative with bags of bread, potato or grains
Examine the bags for growth. Do not open the bags!

After the experiment pour a bit of bleach in each bag and dispose of them far from students.

Discussion
Ask: Why are cups B (with unwashed hand) and D (with yucky stuff) murky, but not A (nothing dipped) or C (washed hand)?

Key Words
Experiment, Prevention, Diarrhea, Handwashing, Soap